The present proposal is to develop standardized tests for detecting and confirming active Tuberculosis in patients using serological methods in combination with novel recombinant antigens that have been identified and shown to be diagnostic for TB. The disease is a worldwide problem and is one of the leading causes of death in the developing world. It is estimated that in 195, 1.9 billion individuals were carriers of the disease and that 8.9 million new cases developed active disease. In 1995 3.1 million died from the disease. The need for tests to be able to differentiate between active and inactive disease is therefore important. The proposed studies will enable the development of standardized tests (ELISA and immunoblot) using novel recombinant antigens that have been shown to differentiate PPD+ individuals from active TB patients. The proposed studies will lead to inexpensive, reliable tests that will serve a large market. The development of such tests will capitalize on Corixa's established collaboration with investigators in developing countries which has provided access to an extensive serum bank. This will be used in assessing the clinical sensitivity and specificity of the tests developed. PROPOSED COMMERCIAL APPLICATION: The detection of active TB both in the U.S and the world can lead to significant savings in health costs. In terms of market potential the estimated worldwide sales of such tests would be in excess of $100 million, based on a cost of $1 per test.